Abstract: The oil-impregnated paper (OIP) bushing is an important part of oil-immersed transformer. To realize the internal temperature monitoring of the bushing, a design scheme of wrapping single-mode optical fiber and multi-mode optical fiber in parallel around the outside of the capacitor core is proposed, and the Brillouin optical time-domain analysis and Raman optical time-domain reflection fiber sensing technology are employed to monitor its temperature in full time and space. By using the finite element simulation calculation, it is found that the change in local electric field intensity of the bushing before and after the deployment of fiber optics is small, from 0.673 kV/mm to 0.752 kV/mm. At the same time, the thermal aging test of the fiber optics is conducted to verify the feasibility of the scheme and an optical fiber composite 110 kV oil-impregnated paper bushing is developed. At an applied voltage of 126 kV, the partial discharge of the bushing is 5.03 pC, which meets the national standard requirements. Subsequently, the bushing temperature data are measured by temperature rise tests and the temperature field simulation is performed. The measured data show that the axial temperature difference between the surfaces of the bushing reaches 45.2 ℃, while the axial temperature difference between the inner core is only 6.7 ℃. Combined with the simulation results, it is inferred that there are upper and lower oil circulation inside the bushing and the oil flow directions are opposite. The development of this bushing can provide a new idea and reference for the condition monitoring of OIP bushing.